Starch- and cellulose-related microbial diversity of soil sown with sugarcane crops in the Papaloapan Basin, a megadiverse region of Mexico

Abstract

<jats:p>Introduction: Sugarcane is an essential agricultural product for bioethanol production in Mexico. The discovery of both the bacterial community associated with this crop and the soil status is a decisive step towards understanding how microorganisms influence crop productivity. Culture enrichment allows for the identification of the biodiversity of biological samples. The objective of this research was to identify the bacterial biodiversity related with two complex carbohydrate sources (starch and cellulose) in soils sown with sugarcane in the Papaloapan Basin in Oaxaca, Mexico via a metagenomic approach. Method: Soil content was analyzed chemically. Liquid LB, LB-starch and LB-1% carboximetilcellulose media were inoculated with 2 g soil and cultured at 180 rpm, 37°C for 48 h. The biomass was collected and the 16S rDNA gene was amplified and a library was constructed which was analyzed by sequencing.Results: N, K and Zn content of organic matter showed higher values than average, as opposed to P and Na, which were lower than average. In the library, 35 OTUs related to Clostridium, Bacillus, Enterococcus, Lysinibacillus and Citrobacter genera were found which could contain genes for breaking cellulose and starch.Discussion or Conclusion: This is the first approach to identify the diversity related to starch and cellulose hydrolysis in the Papaloapan region, where the principal genera detected were Clostridium, Bacillus, Enterococcus, Citrobacter and Lysinibacillus in a soil moderately rich in organic matter.</jats:p>

The difference between cellulolytic ‘culturomes’ and microbiomes inhabiting two contrasting soil types

“…Despite the apparent simplicity of the culturing procedure for cellulolytic bacteria, there is still a lack of comprehensive studies devoted to the biodiversity of microbiomes inhabiting several climatic zones. Known studies with similar goals focused on microbiomes of the Brazilian mangroves [ 10 ], sugarcane plots in Mexico [ 11 ], or paddy fields in Hainan [ 12 ], which all are very specific biomes. Considering the wide fluctuations in the composition of the soil microbiome depending on climate changes [ 13 ], we still have much to explore in terms of the biodiversity of the microbial consortia inhabiting climatically unstable subtropical and temperate regions.…”